title: Electrocardiogram characteristics of methadone and buprenorphine maintained subjects.
abstract: There has been recent concern about the association between high dose methadone and prolongation of QTc in the electrocardiogram. QTc is the time from the beginning of the QRS complex to the end of the T have as measured on an electrocardiogram and corrected for heart rate. To date, no association has been made between methadone and buprenorphine in commonly used doses and prolonged QTc. Electrocardiograms were performed on groups of methadone (n = 35, mean daily dose +/- standard deviation, 69 +/- 29 mg) and buprenorphine (n = 19, mean daily dose 11 +/- 5 mg) subjects and a group of non-opioid dependent controls (n = 17). Mean QTc did not differ (p = 0.45) between methadone, buprenorphine, or controls. Methadone subjects were significantly (odds ratio of 7.8) more likely to have U waves than buprenorphine and controls combined. Methadone subjects with U waves were maintained on higher (p = 0.004) doses (89 +/- 29 mg/day) than methadone subjects without U waves (60 +/- 24 mg/day). Methadone subjects taking 60 mg and above had higher (p = 0.02) QTc (405 +/- 29 milliseconds) than methadone subjects taking less than 60 mg per day (381 +/- 27 milliseconds). Although an association is thought to exist between high methadone doses and elongated QTc, methadone and buprenorphine, at commonly used daily doses, remain safe agents for opioid substitution therapy.
authors.affiliation: Faculty of Health Sciences, University of Adelaide, South Australia 5005. peter.athanasos@adelaide.edu.au
authors.forename: Peter
authors.initials: P
authors.lastname: Athanasos
authors.forename: Aaron L
authors.initials: AL
authors.lastname: Farquharson
authors.forename: Peggy
authors.initials: P
authors.lastname: Compton
authors.forename: Peter
authors.initials: P
authors.lastname: Psaltis
authors.forename: Justin
authors.initials: J
authors.lastname: Hay
mesh_terms: D000328:Adult; D002047:Buprenorphine / Q000009:adverse effects* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography / Q000187:drug effects*; D005260:Female; D006801:Humans; D008133:Long QT Syndrome / Q000139:chemically induced* / Q000175:diagnosis; D008134:Long-Term Care; D008297:Male; D008691:Methadone / Q000009:adverse effects* / Q000627:therapeutic use; D008875:Middle Aged; D009294:Narcotics / Q000009:adverse effects* / Q000627:therapeutic use; D009293:Opioid-Related Disorders / Q000534:rehabilitation*; D012307:Risk Factors
chemical_list: D009294:Narcotics; D002047:Buprenorphine; D008691:Methadone